CYGNSS_L2_V2.0_1

PODAAC-CYGNS-L2X20

Version 1

AbstractThis dataset contains the Version 2.0 CYGNSS Level 2 Science Data Record which provides the time-tagged and geolocated average wind speed (m/s) and mean square slope (MSS) with 25x25 kilometer resolution from the Delay Doppler Mapping Instrument aboard the CYGNSS satellite constellation. This version supersedes Version 1.1. The reported sample locations are determined by the specular points corresponding to the Delay Doppler Maps (DDMs). A subset of DDM data used in the direct processing of the average wind speed and MSS is co-located inside of the Level 2 data files. Only one netCDF data file is produced each day (each file containing data from up to 8 unique CYGNSS spacecraft) with a latency of approximately 6 days (or better) from the last recorded measurement time. The Version 2.0 release represents the first science-quality release that has moved beyond the previous "Provisional" releases (i.e., Version 1.0 and 1.1). Here is a summary of improvements that reflect the quality of the Version 2.0 data release: 1) more accurate Geophysical Model Function (GMF) at low to moderate wind speeds (1-25 m/s) using a larger training set of coincident matchups with ground truth wind speeds; 2) First time use of GMF at storm force wind speeds (> 30 m/s) based on coincident matchups with ground truth wind speeds measured by the Stepped Frequency Microwave Radiometer on board the NOAA P-3 hurricane hunter airplanes during eyewall penetration of major Atlantic storms in summer/fall 2017; 3) Improved debiasing algorithm for L2 retrieval algorithm at low to moderate wind speeds using matching method between CYGNSS and ground truth measured cumulative distribution functions of wind speed over large global sample populations.